Australia play two Tests and four limited-overs matches against Pakistan in the Middle East in October and November.
And Johnson's involvement was put in jeopardy on Friday when Cricket Australia (CA) announced they would not release him for the Champions League Twenty20 with Indian franchise Kings XI Punjab.
CA said that Johnson was "not back to 100 per cent fitness" but just two days later, Johnson revealed he was feeling good.
"I've had a little bit of a rib thing going on," Johnson told Fox Sports News.
"It's something that reoccurs. We've got a fair bit of cricket coming up in the next 12 to 18 months [so I've had some extra rest].
"It's feeling really good now."
Australia captain Michael Clarke is also under a fitness cloud after injuring his troublesome hamstring on their recent one-day tour to Zimbabwe.
Johnson feels Clarke's presence on the UAE tour will be critical, though, given the inexperienced Test squad.
"I hope he gets his fitness up," he added.
"He obviously struggled in Zimbabwe with his hamstring but we need him there. He's our captain.
"There's a few inexperienced guys going over there, some young guys, so to have his experience … we really need him over there."
Pakistan's chief spinner, Saeed Ajmal, has been banned by the International Cricket Council after his bowling action was deemed to exceed the 15-degree level of tolerance.
Johnson feels Ajmal's absence will "definitely help" Australia, while acknowledging that playing spin better was an area the batsmen were targeting.
"To play spin and to do it well … it's probably something we [struggled with] in Zimbabwe," he said.